The frequency thresholds are calculated from an adaptive procedure where deltaF is decreased when a wrong answer is provided and increased for a right answer.
The evolution of the delta F values across trials for the detection and identification tasks is ploted bellow:
The thresholds are calculated from the DeltaF values corresponding to the last 10 reversals. The procedure was repeated two times before training (sessions 1 and 2) and two times after (sessions 3 and 4). The figure bellow shows these thresholds across sessions for the detection and identification conditions:
The threshold scores are the means of the four session (two pre-test and two post-test)
Here are the plots of scores, accuracy and duration in function of trials. The accuracy is the difference between the choosen tone and the highest tone. The duration is the length in seconds of each trial from the begining of the sound to the answer. The score is a mixed value calculated from accuracy and duration according to this equation:
\[ (\frac{1}{(\frac{duration}{100}+1)^2} + 1) \times 600 \times (\frac{accuracy}{100})^2 \]
Thus, the time score is a multiplier between 1 for a very long trial and 2 for a very short one (few seconds). Thus, the accuracy score can be doubled with speed.
The accuracy score is 600 maximum (the idea was to make a score in order to have the pleasure to cross 1000 points when the performance is good). For accuracy and time, the power function is used to provide the maximum of points near the perfect score and have a lot of difference when it is harder.
UPDATE:
The equation used from va01 (20/07/15) was modified to have a more steeper curve and invite people to be more accurate and avoid the strategy to make a lot of trial quickly and win a lot of points:
\[ (\frac{1}{(\frac{duration}{100}+1)^2} + 1) \times 600 \times (\frac{accuracy}{100})^6 \]
The variability of the results is not associated with duration. Each point is a trial.
The frequencies used in the mountain task are randomly taken from 400 Hz to 2400 Hz.
The mean thresholds are calculated from all participant’s deltaF for each session (first and second in pre-test and third and fourth in post-test) and condition (detection and identification).
Thresholds are also calculated in percent of the first session deltaF.
The equation used to calculate the total score take into account the global scores to the mountain task of each session, the mean accuracy of all mountain task sessions and the results to each threshold tasks:
\[ ScoreTotal + (1000 \times meanAccuracy) + \frac{20 000 000}{deltaFIdentification} + \frac{20 000 000}{deltaFDetection} \]
\[ 349715.27 + (1000 \times 561.79) + \frac{20 000 000}{174.28} + \frac{20 000 000}{78.16} = 1282138.43 \]
\[ 187007.97 + (1000 \times 529.45) + \frac{20 000 000}{241.2} + \frac{20 000 000}{74.01} = 1069617.78 \]
The frequency threshold tests are done before and after each training session. The dotted vertical lines correspond to each first threshold task.
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